Funny -- when McCain traveled overseas, it was obvious that he was engaging with issues on which he had a lot of knowledge and familiarity, which is why it worked politically. He essentially met up with "old friends" in places he'd been before.
Barack Obama is going overseas to get a look at things for the first time and to meet everybody. No doubt it is one more maneuver intended to help us "see" Barack as president and a hasty effort to gain a little credibility in discussing foreign affairs.
But it does seem to point up Barack's inexperience vis a vis John McCain.